Antenna system



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` ANTENNA SYSTEM y Filed June 14, 1959 UNITED STATES `Pltl'fllltl'fOFFICE ANTENNA. SYSTEM Hans Eggers, Berlin, Germany, assigner to C.Lorenz Aktiengesellschaft, Berlin-Tempelhof, Lorenzweg, Germany, acompany Application June 14, 1939, Serial No. 279,001 In Germany June24, 1938 2 Claims. (Cl. 25u- 33) This invention relates to antennasystems, and ture that the antenna system will receive unimoreparticularly to antennas employed for wirefcrmly from and radiateuniformly into each less signalling on movable vehicles, such as airandevery compass direction since the effective planes. directionalcharacteristic thereof will not be in- .An antenna arrangement mountedon board iiuenced when the supporting surfaces are moved aircraft forreceiving and/or radiating space out of the horizontal plane in responseto a Waves customary consists of a vertical dipole deviation from thestraight course line of flight. extended either upwards or downwardsfrom the My invention will be more readily understood body of anaeroplane and connected with a wirefrom the following description takenin conjuncless receiver and/or transmitter through contion with theaccompanying drawing, in which 10 ductors or cables, respectively.However, such Fig. 1 schematically shows an airplane which arrangementsuffers under the fundamental disis provided with an antenna systemaccording `to advantage that the electromagnetic eld received thisinVentOn. While Fig. 2 shows radiation diaand/or radiated isconsiderably aiected by the grams explanatory 0f my invention.

l5 metallic structure of an airplane and in par- In Fig. 1 referencenumeral l denotes the me- 15 ticular by the metallic supporting surfacestheretalliC strueture 0f an airplane An upper Verof, from which followsthat neither the action tical dipOle 2 and a IOWer Vertical dilfJOle 3dis'- of reception nor of radiation is uniform in the POSed in alignmentWith One another are inhorizontal plane, since instead of the desiredsulatingly fixed on the upper respectively lOWer 2o circuler radiationdiagrams considerably dispart of the airplane and are Connectedpreferably 2o torted diagrams are obtained which present one in parallelto a wireless receiving and/ 01 transor more maxima or minima,respectively. Such mitting apparatus 6 through Conductors 4 anddistortion becomes still more harmful when the 5, reSDeCtiVelyairplanebanks, that is, deviates from a, straight The different horizontaldirectional characline course in which case the supporting surteFistiCS0f the antenna arrangement 0f Fig. 1 25 faces or wings on account oftheir deviation from are ShOWn in Fig- 2 The diagram a is that 0f thehorizontal plane act as additional shieldings. the upper VertiealdilOOle 2 alone and the diagram It is thus impossible to assuresatisfactory wirel1' is that 0f the lOWer Vertical dipOle 3 alOne. lesssignalling or even to accurately determine The tWO diagrams d and b arenOtOngruOuS but the sense of direction of the electromagnetic the 0n@ isSubstantially the true refleet-t0n 01 30 waves in eases that theantenna, means fol-m image of the other since the minimum of the oneDart Of a direction finding system. diagram is located almost in themaximum of Itis an object of my invention to provide means the otherdiagram. Because of the fact that in order to satisfactorily eliminatethedisadvanthe tWO Vertical dipeles Originating these diatages mentionedin the foregoing, and this is grams ate Connected in Parallel t0 theWireless 35 achieved according to the main feature thereof Signallingapparatus, the resultant diagram C is by employing in an antenna, System0f an airobtained which presents neither minima nor plane or the like n.plurality of antennas which maxima and which substantially involvescircuare simultaneously effective and by so placing lar shape. Now, ifthe airplane differs from the these antennas partially on the upper andparstraight Course s0 that the supporting Surfaces 40 tially on thelower portion of the airplane that become inclined with respect to thehorizontal the directional characteristics thereof mutually Plane, eaeli0f the individual radiation diagrams supplement each other for securingreception is subjeeted t0 a Change but the resulting diaand/or radiationwhich is uniform in each and grain C 0f the tWO individual diagrams in000i)- every compass direction, In gne specn aspect eration with oneanother remains substantially of my invention, the antenna systemcomprises unellanged- It is thus possible as a result 0f tivo individualantennas one of which projectthe novel antenna arrangement as proposedin ing upwards and the other of which projecting this invention tosecure reception and/or radiadownvvards from the upper respectivelylower tion which is uniform and equal in all 00mpart of the airplane.These two antennas are Dass direCtiOnS Whether the airplane nies on a 50preferably vertical dipoles which in accordance straight course line orbanks.

with a further feature of this invention are po- The facility accordingto this invention to sitioned in alignment the one above the othervertically mount the two dipoles in alignment above and below theairplane. one above the other involves the further advan- This novelfacility involves the benecial featage that no additional directionalaction is set 55 up in the horizontal plane in response to transit timedifferences between the two individual dlpoles.

What is claimed is:

1. A wireless signalling equipment for use on board aircraft comprisinga wireless signalling apparatus, an antenna system consisting of twoindividual antennas substantially omnidirectional in the horizontalplane of the craft one positioned above and the other disposed belowsaid aircraft in substantially vertical alignment with one another andeach normally setting up a radiation diagram subject to deformation bysaid aircraft, and means for connecting said upper and said lowerantenna in parallel to the said Wireless signalling apparatus forsimultaneous operation Whereby said radiation diagrams mutuallysupplement each other to produce a resultant radiation diagram ofsubstantially circular configuration and uniform action in all compassdirections.

2. The invention according to claim 1, characterized in that the saidindividual antennas are vertical dipoles.

HANS EGGERS.

